Study on Rough Filtration Plus Slow Sand Filtration Techniques for Cellar Water of Villages and Towns in Northwest China

摘要

Based on the turbidity, lower temperature and micro-pollution of cellar water in villages and towns in northwest China, removal efficiency of turbidity. Results showed that the turbidity in yielding water became stable and the average removal rate reached 92%, 20%, 32%, 32%, 22% respectively after operating integrate technology for 25 days. After cellar water was treated through rough filtration plus slow biological filtration technics, all indexes above accorded with the standards of drinking water quality. Thus, this integrate technology can be used to reprocess the diminutive and scattered cellar water of villages and towns in northwest China. In recent years, effectively accumulated the cellar and made full use of the natural rainfall by organizing and implementing the rain collector engineering in arid and semi-arid area of Gansu province, to a great extent, played an important role in easing the shortage of water resources situation, in development of local economy and in the improvement of living [1]. Rainwater stored in the cellar was polluted by solid debris (trash, animal waste, etc), air fallout, chemical fertilizers, pesticides, vehicle emissions and other pollution from human activity. In addition, the rainwater stored in the cellar for a long term always cause water metamorphic and stale, drinking of which will be pernicious to human beings and livestock. Our tests found that cellar water, in which chrominance and turbidity is terrible, suffered from heavy metal pollution in different degrees was smelly and had the fishy smell while microbe, organic matter and total nitrogen in water always exceeded the standards of drinking water. The water will not be qualified for drinking without necessary cleansing measures [2]. According to the characteristics of the units, this paper developed laboratory research, optimization and integration for rough filtration plus slow sand filtration with the advantages of low cost, simple operation and being as a dispersive unit. And this paper is also set up to test the removal efficiency of the rainwater storage through the experimental study, and tries to seek a solution to problems of safety for drinking water in northwest arid area.